Building

Dependencies

Compiling

A D compiler and DUB
should be installed. Compiling works with LDC and DMD, other compilers have not been tested.

Then use:

dub build --build release

It is necessary to build in release mode to have the performance required for the emulator to run at full speed.

LDC has better performance over DMD, use the --compiler ldc2 option to enable it.

Running

Use:

dub run --build release -- (arguments)

Again, use --compiler ldc2 option to enable LDC.

Or get the binary from the bin folder after building and use:

./gbaid (arguments)

Arguments

At minimum, you must specify the path to the bios and rom images with

-b (path to bios) (path to rom)

The following arguments are also recognized:

Long form

Short form

Argument

Usage

--bios

-b

Path to bios

Specify bios image

--save

-s

Path to save

Specify path for loading and saving saves

--noload

-n

None

Don't load the save

--nosave

-N

None

Don't save the save, either on exit or quick save

--scale

-r

Scaling factor (float)

Draw the display at "factor" times the original resolution

--fullscreen

-R

None

Display in full screen mode (--scale will be ignored)

--filtering

-f

LINEAR or NONE

What technique to use to filter the output texture to be drawn to the screen

--upscaling

-u

EPX, XBR, BICUBIC or NONE

What technique to use to increase the resolution of the drawn texture

--controller

-c

None

Enable the controller as an input method

--raw-audio

N/A

None

Don't filter the audio output of the emulator; will generally be noisier

--save-memory

N/A

See saves section

What memory configuration to use for the main save

--eeprom

N/A

See saves section

What memory configuration to use for the EEPROM

--rtc

N/A

See saves section

What memory configuration to use for the RTC

Note that these arguments are case sensitive and that bundling is only supported by the --noload and --nosave switches.

Saves

Saves use a custom format and .gsf extension that is not compatible with other emulators. If no save path is specified,
the same path as the ROM is used, but with the .gsf extension instead of whatever the ROM image is using. If no save is
found matching either the given or default path, then a new save is created using that path. Saves are overwritten on exit,
unless the --nosave argument is used.

The emulator can almost always auto-detect the save type, but it's not guaranteed to always work. If it doesn't work, then you will need to
use the following switches to configure the save memory manually.

The --save-memory switch is used to configure the main save memory. It takes any one of the following arguments (case senstive).

Argument

Description

SRAM

64KB of static RAM

FLASH_512K

512Kb of Flash

FLASH_1M

1Mb of Flash

NONE

No main save memory

AUTO

Decide from the ROM

The --eeprom and --rtc switches are used to configure the optional EEPROM and RTC respectively.
They take any one of the following arguments (case senstive).

Argument

Description

ON

Enabled

OFF

Disabled

AUTO

Decide from the ROM

These flags are only needed when creating a new save, after that the format is saved in the save file.

GBA controls

These will be re-mapable in a future version.

Gamepad

Keyboard

Controller

A

P

A

B

L

B

Up

W

D-pad or L-stick

Down

S

D-pad or L-stick

Right

D

D-pad or L-stick

Left

A

D-pad or L-stick

R

R-shift

RB or RT

L

L-shift

LB or LT

Start

Enter

Start

Select

Tab

Select

Emulator controls

These will be re-mapable in a future version.

Function

Keyboard

Controller

Quick save

Q

X

Quick saves are not save states, they just write the contents of the save memory to the save file immediately.
Otherwise this is only done on exit. This is useful to ensure you do not loose game progress if the emulator crashes
or fails to close normally. Note that quick saves are disabled when using the -N switch.

Upscaling

All upscaling is implemented as OpenGL shaders.

EPX is a simple but fast 2x upscaler.

XBR is a 5x implementation, it gives better results, but is slower.

BICUBIC is an interpolation method that offers better results than linear filtering at a greater cost.
It upscales to whatever is defined by the --scale switch so it should always be used with this method.

When you use the --upscaling switch you should also use the --scale switch with the appropriate factor for the selected algorithm
(unless you are using the full screen mode).